On 2022-11-14 04:41, Aaron Ballman wrote:
it's generally a problem when autoconf relies on invalid language constructs
Autoconf *must* rely on invalid language constructs, if only to test whether the language constructs work. And Clang therefore must be careful about how it diagnoses invalid constructs. Clang shouldn't willy-nilly change the way it reports invalid constructs, as that can break Autoconf.
issues of security like statically known instances of UB
It's fine to report those; I'm not saying don't report them. All I'm saying is that Clang should be careful about *how* it reports them.
At the very least if there are going to be changes in this area, the Clang developers should notify Autoconf (and presumably other) downstream users of the changes, and provide a supported way to get the old behavior for reporting, and give downstream time to adapt.
